Gerald barker



(No Model.)

G. BARKER.

- YVELOGIPEDE .DRIVINGYGEAR.

WITNESSES NITED ST TEs GERALD BARKER, OF LONDON, ENGLAND.

VELOC IPEDE DRIVING-G EAR.

SPECIFICATION forming part of Letters Patent No. 601,824, dated April 5,1898.

Application filed November 27, 1896. Serial No. 613,517. (No model.)Patented in England November 16, 1894,110. 22,151;

in France August 29, 1895, No. 249,956; in Belgium August 30, 1895, No.117,325, and in Germany $eptember 7, 1895,

To all whom it may concern.-

Be it known that I, GERALD BARKER, a subject of the Queen of GreatBritain, residing at Westminster, London, England, have invented new anduseful Improvements in Velocipede Driving-Gear, (for which I haveobtained patents in the following countries: Great Britain, No. 22,151,bearing date November 16, 1894; France, No. 249,956, bearing date August29, 1895; Belgium, No. 117,325, hearing date August 30, 1895, andGermany, No. 86,700, bearing date September 7, 1895,) of which thefollowing is aspecificati'on.

This invention relates to the crank drivinggear of velocipedes. e

The main object is to increase the speed and render the propulsioneasier by applying the pressure upon the pedals to greater advantage.

The invention consists, essentially, in'providing mechanism for causingthe pedals to travel around the main crank-spindle in a somewhateccentric or elliptical path or course. Whendesce'nding, the pedals areat an increased distance from the crank-spindle and power is thereforeapplied to greater advantage. When the pedals are ascending, they are ata reduced distance from the crankspindle. By the above means theadvantage of a long crank-throw is obtained without the fatigueconsequent upon the feet having to travel around the spindle at a largerradius.

In carrying my invention intopracticel cause the crank-spindle to passthrough the center of the driving wheel'or wheels, and the said spindleis attached directly thereto or power is conveyed to the said wheels bysuitable gear. If desired, the crank-spindle is mounted in separatebearings and power is conveyed to the driving wheel or Wheels by anendless chain or chains,'gear-wheels, or the like, and the somewhateccentric or elliptical course or path of the pedals is obtained asfollows: Secondary cranks, crank-wheels, or crank-disks have theirspindles mounted in bearings at the outer ends of the-main cranks,crank-wheels, or crank-disks, the pedal-pins being fixed to the outerends'of the secondary cranks or near the periphery of the crankwheels ororankdisks. Toothed planetwheels keyed or otherwise attached to thesecondary crank-spindles, crank-wheels, or crank-disks engage directlywith stationary toothed sun-wheels of the same diameter as theplanet-wheels and concentric with the main crank-spindle. The centers ofthe sun wheels must coincide with the center line or axis of the maincrank-spindle. wheels are preferably bored out, so that the maincrank-spindle passes through them'without touching, in order to avoidfriction and provide roomfor the crank-spindle bearings.

In the drawings, Figure 1 is an elevation, and Fig. 2 is a plan, ofdriving-gear constructed in accordance with my invention. ais part ofthe framework'of a velocipede. b is the main crank-spindle. c is achain-Wheel secured to the crank-spindle b and giving n10- tionby meansof a chain in the usual manner to the rear wheel of. a bicycle. Two arms0 of the said wheel, together with bow or divided rim 0 form the maincranks at one end of the spindle. c is the main crank at the other endof the spindle. The crank 0 also carries a bow 0 d are secondarycrankspindles carried in bearings in the bows 0 e are secondary cranks.fare the pedal-pins and pedals. g are toothed planet-wheels secured tothe secondary crank-spindles d and gearing with stationary sun-wheels h,secured by set-screws or other suitable devices 11 to the framework a,or by brazing to the bracket a. The sun-wheels h are bored out toreceive or allow room for the bearings for the main crank-spindle b. Thesun-wheel may consist of a toothed ring attached to the frame byset-screws or the like passing through slots in the said ring, so as toallow the angle of leverage to be readily adjusted. If the slots aresymmetrically placed, the sun-ring may be turned partly around its axisfrom time to time to insure even wear. Planet-wheels may be similarlyconstructed.

Fig. 3 is a modification of gear similar to that described in Figs. 1and 2, with the exception that the bows or divided rim or end isdispensed with and that the secondary crank-spindles d are carried in abearing or hearings in bosses c on the arms a of the chain-wheel c orcrank 0 When the main The suncrank-spindle 1) passes through the centerof the driving-wheel and is attached or geared thereto-say as in afront-driving bicycle a crank similar to c is used instead of the chainvheel. This applies to both Fig. 1 and Fig. 3.

Fig. 4: is an elevation, and Fig. 5 is a plan, showing a modification ofdrivinggear in which crank-arms a, secured to the main crank-spindle I),carry fixed crank-pins which serve as secondary crank-spindles (Z,around which the secondary cranks e and planetwheels g rotate. Theplanet-wheels g engage with thesun-wheels h, as before described. \Vhenchain-wheels are used, the crank-arms c are secured to the chain-wheel cby setscrews or other suitable devices j, as shown.

Fig. 6 is an elevation of gear similar to that described under Figs. 4and 5, with a large chain-wheel 0 formed solid with the arm a of themain crank and of such diameter as to include the boss 0 for thesecondary crankspindle cl within the rim of such chain-wheel.

Fig. 7 is a diagram showingthe position of the main crank-spindle Z2,secondary crankspindles d, and pedal-pins and pedals f at various pointsduring a complete revolution, the arrow showing the direction of motion.

On reference to the above diagram it will be seen that whenapplyingpower the pedals travel quickly down through an increaseddistance as compared with pedals attached directly to a Inaincrank-pinand that during the remainder of the revolution the pedals pass upwardthrough a decreased distance, the pedals being at a greater distance.from the spindle h during the downstroke than during the upstroke. Ifthe secondary cranks are, as I prefer, one-quarter of the length of themain crank, the pedals travel fifty per cent. faster and farther duringa portion of the downstroke, the increased leverage being thereforetwice that due to the eccentricity. During the downstroke it will beseen that the pedals overtake and pass the main crank and secondarycrank-spindle end, but that the latter recover their lead during theupstroke.

In all the views the plane of greatest leverage is horizontal, but byengaging any particular teeth of the sun and planet wheels and bypartially rotating the sun-Wheels when slotted connections are used theplane of greatest leverage may be varied to such angle as may be foundto be most advantageous according to the positionof the saddle. Thesun-wheels may be made to form part of the framework of the velocipede,and so give increased stiffness thereto.

IVhat I claim as my invention, and desire to secure by Letters Patent,is-

I11 velocipede driving-gear,the combination with the main cranks, ofsecondary cranks mounted thereon provided with planetwheels, andstationary externallytoothed sun-wheels with which said planet-wheelsengage, said sun and planet wheels being of the same size, and pedalsupon the secondary cranks.

In testimony whereof I have hereunto set my hand this 3d day ofNovember, 1896.

GERALD BARKER.

IVitnesse-s:

JOSEPH J EB. TAYLOR, THOMAS GEORGE BocKINe.

